Many compounds can exist in different crystal forms, or polymorphs, which exhibit different physical, chemical, and spectroscopic properties. For example, certain polymorphs of a compound may be more readily soluble in particular solvents, may flow more readily, or may compress more easily than others. See, e.g., P. DiMartino, et al., J. Thermal Anal., 48:447-458 (1997). In the case of drugs, certain solid forms may be more bioavailable than others, while others may be more stable under certain manufacturing, storage, and biological conditions.
Polymorphic forms of a compound are known in the pharmaceutical arts to affect, for example, the solubility, stability, flowability, fractability, and compressibility of the compound, as well as the safety and efficacy of drug products comprising it. See, e.g., Knapman, K. Modern Drug Discoveries, 2000, 53. Therefore, the discovery of new polymorphs of a drug can provide a variety of advantages.
The identification and selection of a solid form of a pharmaceutical compound are complex, given that a change in solid form may affect a variety of physical and chemical properties, which may provide benefits or drawbacks in processing, formulation, stability, bioavailability, storage, handling (e.g., shipping), among other important pharmaceutical characteristics. Useful pharmaceutical solids include crystalline solids and amorphous solids, depending on the product and its mode of administration. Amorphous solids are characterized by a lack of long-range structural order, whereas crystalline solids are characterized by structural periodicity. The desired class of pharmaceutical solid depends upon the specific application; amorphous solids are sometimes selected on the basis of, e.g., an enhanced dissolution profile, while crystalline solids may be desirable for properties such as, e.g., physical or chemical stability.
Pomalidomide has a chemical name of 4-amino-2-(2,6-dioxopiperidine-3-yl)isoindoline-1,3-dione. Pomalidomide is a compound that inhibits, for example, LPS induced monocyte TNFα, IL-1β, IL-12, IL-6, MIP-1, MCP-1, GM-CSF, G-CSF, and COX-2 production, and may be used in treating various disorders. See, e.g., U.S. Pat. Nos. 5,635,517, 6,316,471, 6,476,052, 7,393,863, 7,629,360, 7,863,297, 8,198,262, 8,673,939, 8,735,428, 8,759,375, 8,722,647, and 9,282,215. Pomalidomide has direct anti-myeloma tumoricidal and immunomodulatory activities, and inhibits stromal cell support for multiple myeloma tumor cell growth. Pomalidomide inhibits proliferation and induces apoptosis of hematopoietic tumor cells. Additionally, pomalidomide inhibits the proliferation of lenalidomide-resistant multiple myeloma cell lines and synergizes with dexamethasone in both lenalidomide-sensitive and lenalidomide-resistant cell lines to induce tumor cell apoptosis. Pomalidomide enhances T cell- and natural killer (NK) cell-mediated immunity, and inhibits production of pro-inflammatory cytokines (e.g., TNF-α and IL-6) by monocytes. Pomalidomide also inhibits angiogenesis by blocking the migration and adhesion of endothelial cells. A molecular target of pomalidomide is cereblon, a protein that forms a ubiquitin E3 ligase complex with DNA damage-binding protein (DDBA), culin 4 (CUL4) and protein Roc 1. Pomalidomide binding to cereblon induces the polyubiquitination of two substrate proteins Ikaros (IKF1) and Aiolos (IKZF3). Pomalidomide is known to have CNS penetration. Due to its diversified pharmacological properties, pomalidomide is useful in treating, preventing, and/or managing various diseases or disorders.
Pomalidomide and methods of synthesizing pomalidomide are described, e.g., in U.S. Pat. Nos. 5,635,517, 6,335,349, 6,316,471, 6,476,052, 7,041,680, 7,709,502, and 7,994,327. The chemical structure of pomalidomide has been known since at least the 1960s, but little is known regarding solid forms. An amorphous solid and one crystalline form (anhydrous) have been described in WO 2013/126326. A novel crystalline form of pomalidomide is described herein.
Pomalidomide is the active ingredient in POMALYST®, which in combination with dexamethasone was approved by the FDA in 2013 for the treatment of patients with multiple myeloma who have received at least two prior therapies including lenalidomide and a proteasome inhibitor and have demonstrated a disease progression on or within 60 days of completion of the last therapy. The label for POMALYST® can be found at http://www.pomalyst.com/?pi=yes&gclid=CMP4keDY-tMCFZOCfgods7oPsA.
New polymorphic forms of 4-amino-2-(2,6-dioxopiperidine-3-yl)isoindoline-1,3-dione can further the development of formulations for the treatment of chronic illnesses, and may yield numerous formulation, manufacturing and therapeutic benefits.